Safety switch



March 24, 1959 w. H. THOMPSON 2,879,349

' SAFETY SWITCH Fil ed Oct. 10. 1957 2 Sheets-Sheet 1 4? INVENTOR. /7 7ZiZZiamH.Thompson ATTC! RN EYE March 24, 1959 w, THOMPSON 2,879,349

SAFETY SWITCH 2 Sheets-Sheet 2 Filed Oct. 10, 1957 xa WiZZ iamfi. Thompson INVENTOR.

ATTD R N EYS United States Patent i This invention relates to a safety switch.

The object of the invention is to provide a safety switch which will serve to interrupt or break an electrical circuit in a vehicle, airplane or the like, in the event of an accident or impact whereby the danger of a fire start- 'ing after a wreck from gasoline becoming ignited, will be minimized.

Another object of the invention is to provide a safety:

switch for use with a vehicle ignition system or the like, the safety switch of the present invention including a movable element that is adapted to be moved from a predetermined position upon impact so that an electrical circuit will be interrupted whereby the danger of gasoline being ignited by an electric spark is prevented or minimized, there being a means provided for resetting the switch after it has functioned.

A further object of the invention is to provide a safety switch which is extremely simple and inexpensive to manufacture.

- .Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same.

Figure 1 is an elevational view showing the safety switch of the present invention.

, Figure 2 is a vertical sectional view taken through the safety switch, and showing the ball and associated parts in one position.

Figure 3 is a view similar to Figure 2, but showing the position of the parts after an impact whereby the electrical circuit is interrupted or broken.

Figure 4 is a view similar to Figures 2 and 3 but showing the parts in a difierent position, as when the switch is being reset.

Referring in detail to the drawings, the safety switch of the present invention includes a hollow housing which is indicated generally by the numeral 10, and the housing includes a horizontally disposed bottom wall 11, up-

standing wall members 12 and 13, an upper flat portion 14,- and an upstanding section or portion 15. A plate or cover 16 is mounted on the top of the upstanding portion 15, as for example as shown in Fig. 2. I

Extending through the bottom wall 11 of the housing 10 is a pair of terminals 17 and 18. A blade or contact member 19 has one end pivotally connected to the upper end .of-the terminal 18 by means of a pivot pin or bolt 20, and the blade 19 is mounted for movement into and out of engagement with a seat 21 which is arranged on the upper end of the terminal 17.

. Arranged in the housing 10 is a movable arm 22 which has a portion pivotally connected at 23 to a lug 24 which depends from the flat portion 14 of the housing. A coil spring 25' has one end connected to an end of the arm 22, while the lower end of the coil spring 25 is connected to an eyebolt or securing element 26 which extends upwardly from the bottom wall 11.

A means is provided for connecting the blade 19 to the Patented Mar. 24, 1959 arm 22, and this means comprises a link 27 which has its lower end connected to the blade 19 by means of a pin or bolt 28. The upper portion of the link 27 is provided with a slot 29, and a suitable pin or bolt 30 extends through the slot 29 and into engagement with the arm 22. A cable or cord 32 extends through an apertured end portion 31 of the arm 22, and the cable 22 is trained over a pulley 33 which is mounted in the lower portion of the housing. One end of the cable 32 is connected to a stop member 34 on the bottom of a coil spring 35, and the upper end of the coil spring 35 is connected to a partition 36 which is arranged in the housing.

The partition 36 is provided with a downwardly recessed portion 37 which has a central opening 38 therein, and a finger 39 extends upwardly from the arm 22 and projects through the opening 38. A cradle or seat 41 is arranged on the upper end of the finger 39, and a ball 40 is adapted to be seated in the cradle 41.

Extending through the plate 16 is a bushing 42, there being a rod 43 projecting through the bushing 42. A

coil spring 44 is circumposed on the rod 43, and the bottom of the coil spring 44 abuts the cap 45 which has a lower recess portion 46 for engagement with a portion of the ball 40.

The numeral 47 indicates a portion of a conventional battery such as a vehicle storage battery, and the battery 47 includes the usual terminal post 48. A conductor 52 has a portion 49 arranged in engagement with the terminal post 48 of the battery 47 and the conductor 52 leads to the terminal 17. A clamping means is provided for connecting the housing 10 to the battery 47, and this means comprises one or more lugs 50 which extend from the housing 10 and may be secured to the battery 47 by means of bolt and nut assemblies 51.

From the foregoing, it is apparent that there has been provided a safety switch which is especially suitable for ues on vehicles such as automobiles, trucks, buses or the like, wherein in the event of an accident, wreck, or impact of sufficient momentum, the ball will be dislodged from its seat or cradle 41 whereby the parts will move from the position shown in Fig. 2 to the position shown in Fig. 3 so that the electrical circuit will be interrupted whereby there will be no danger of gasoline being ignited by the electric spark or current. The safety switch of the present invention serves to disconnect the generator and battery of an automobile, airplane, or the like whether the impact occurs at the front, back, or sides, or whether the vehicle rolls over, and the safety switch will prevent fires from starting after a wreck, since no spark can ignite the spilled gasoline. The metal ball 40 is adapted to be knocked out of the cradle 41 on the finger 39 and when the ball 40 moves from the position, shown in 'Fig. 2, to the position shown in Fig. 3, upon impact, the

.cradle 41 after an accident. The cap 45 has the recessed portion 46 which engages the top of the ball 40, and the rod 43 is adjustable and has a coil spring 44 thereon. The cap 53 is arranged above the coil spring 44. The nut 54 is arranged on the upper end of the sleeve 42 whereby the sleeve 42 can be turned when it is being adjusted, and a lock nut 55 is arranged above the nut 54. The parts can be made of any suitable material and in different shapes or sizes, as for example the housing 10 can be made of plastic. The conductor 52 leads from the terminal post 48 to the terminal 17, and a cable 56 leads from the terminal 18 to the starter post of the vehicle. Lock nuts 57 are arranged in threaded enthe cable 32 tr'ain'ed' thereover.

blade '19 between the terminals 17 and :gagement with thelower portion of the terminal 18. The member 19 constitutes a knife switch blade. The seat 21 is adapted to be lined with lead, and the link 27 moves the'blade 19 wh'en the arm 22 moves. The pulley 33 has The housing '10is connected to the battery'47 by rneans' of the clamp 50. The housing '10 may be'made in sections and such'seetions rnay be connected togetherin'any suitable sion-on the coil spring 25 can be adjustedby means of. the nut-'58, and a lock 'nut-59which is arranged-adjacent 't o the nut '58. The securing element'26is in the nature of an eyebolt. connecting the'conduc'tor 52 to the housing 10. A hold ing nut 61-and a lock nut 62'are also arranged on'the terminal 17. The screw or bolt 51 can be used for fastening the'housing 10to thebattery 47 so as to maintain the-housing securely connected'to the battery. A fia'nged pipe 61 is provided whereby the resetting cable 32 can be hooked to the vehicle-instrument panel, from any direction. A suitable wire'may be connected to the cable 32, and such a who may lead to the instrument 'panel for use when'the switch is to be reset. The resetting mechanism may include a set screw 62 and a wire sleeve 63,andthe'spring 35 serves to keep the flexible cable SZtight, the numeral 34 indicating a connection between the cable 32 and spring'35. A swivel plate 64 may be arranged above the cover 16. The numeral '65 indicates the wire which leads to the generator. Butfer knobs 66 serve to properly 'space the housing from the battery 47 so. as to provide sufiicient clearance for th'e'ter'minal or conductor 52.

The parts may'be lined'with'lead so as to prevent cor- 'rosion and to prevent damage from arcing.

'From'the'foregoing, it isap'pa'rent that'there has been (provided I'a safety switch for use with vehicles, such as automobiles or the like. In use, thes'afety switch is adapted to be arranged in the electrical circuit of the vehicle and normally the'parts arein the positionshown in Fig. 2 so that the current can flow through the switch 18 whereby the vehicle canbe used in'the usual manner. 'However, in the event of an accident, the impact will cause the ball 40 to be knocked oif-of the cradle 41 so that the ball will move from'theposition shown in Fig. 2 for example to the position shown inFig. 3. With the ball'40 off of the cradle 41, the spring 25 will pivot the arm'22 about thepivot pin 23 so that thelink 27 will be moved upwardly. Since thelink 27 is connected to'the switch -blade 19,'it will be seen that theupward-movement-of the link 27 'will causepivotal movement of the-switch -blade-1-9 about an axisextending through the, pin or bolt so that the switch blade 19 will m'oveout of engage- *rnent with theseat 21 whereby the electrical circuit will :be interrupted. The cap 45 serves to normally exert "sufiicient pressure on'the ball 40 so as to prevent 'acci- 5 dental dislodgment'of the ball 40 from its cradle, but -when sufiicient impact occurs, then-the resistance ofthe 'cap 45 can be overcome and the ball 40 canmove 01f .o'f'the cradle.

-Toreset the switch, it is only necessary topull on the 'cableiilgandthe cable-32 may be connected toa suitable knob onthe like onthe instrumental panel of the vehicle. By pulling on the cable 32, the'parts can be pivotedor moved from'the position shown in Fig. 3 to'the positionshown-in Fig. 4, and it will be seen that'in Fig. 4'the cradle il'moves down below theopening 38inf'the "platform 36. "Then,'the ball '40 will roll'down the inclineid surface 37 and be received on the cradle '41. When pressure is released-on the cable '32, the coil'sprin'g '25 will 'move the'par'ts from the position "shown in "Fig. -4the'cradle"4l'rnoves down belowt he opening38 'in'the "cal"cir'c'uit is be used'inthe usual manner.

' "While I "havesho'wn a preferred fo'im'of my invention,

manner. Tencountersunk screws 60 are provided for v again "completed'wherebythe vehicle can I reserve all -rights 'to-such modifications as properly-fall within the scope of the invention as claimed.

I claim:

1. In a safety switch, a hollow housing including a horizontally disposed bottom wall, said housing further including upstanding wall members, a horizontally disposed upper flat portion and an upstanding portion, a plate mounted on the upstanding portion of said housing, first and second spaced apart terminals extending through said bottom wall into'saidhousing, conductor wires connected to said terminals, a conductor leading from said first-terminal to a battery terminal postga's'eat on the upper end of said first terminal, a blade pivotally connected to said second terminal and mounted for movement into and out of engagement with said seat, an arm movably mounted in said housing and having a portion pivotally connected to the fiat portion of said housing, a securing element extendingupwardly from the bottom -'wa11 of the housing, a coil spring having one -'end -con- 'nected to 'said securing element and its 1 other end connected to anend-of said-arm, a link-having its upper end "connected to'said armand its lower endconnected-to said blade, a partition arranged in said housingandincluding a downwardly recessed portion provided with a-central opening, Y a finger extending upwardly from said armand projecting through said opening, 'a cradle on'the upper end "of saidfinger, a ball seated in'saidcradle, abushing mounted in the plate on top of said housing, a rod 'ex tending through said bushing, a recessed cap on the lowe'r 'end of said rodffor engagement with said ball, a

"coil spring'arranged inengagement with said ro'd'and abutti'ng said:cap,apulley-mounted.in the lower portion of the housing, a cable trained-over saidpulley andexitendirig through an end of said arm, and a-coil spring havin'g one end connected to said a cable and itsotherend connected to said partition.

2. The "structure as defined in claim -1, whereinsaid cable is adapted to-beactuated when the switchis to be reset.

:3. The structure as'defined in claim 1, and 'further including clamps for' securing said housingto a'battery.

4. In a safety-switch, a hollow housing-including a bottom wall, a plate mountedon said housing,='first and second spac'e'd apart terminals extending through said bottom wall and into said housing, conductors connected to said terminals, a seat on the upper end ofssaid first terminal, a blade pivotally connected to said second terminal and :mounted i for I movement i into and out of engagement with said seat,"an arm movably mountedrin -said housing and having a portion pivotally-connec'te'd to :said housing, a securing element extending upwardly from the bottom wall of the housing, a coil spring having 'one en'd connected to said securing element and. its 'o'ther end connected-to an end of said arm, a link having Zits :upperiend connected to. said arm' an d' its-lower end 'connected to said blade, a partition arranged in said I housing andi'including a downwardly recessedportion provided with a centralopening;a'finger extending'from said arm -andp'rojecting throughsaid opening, a cradle on the upper end of saidfinger, a ballseatedtin said cradleg-a .-'bushing= mounted in 1 the .plate' on said housing, a'rod extendingthrough said-bushing, a reset cap onthe lower "end .of said'rod for'engagement withsaid ball, :':a Coil "spring arranged on said rod and abutting said :lcap, 1a tpulley mounte'd'in thelowerportion .of the:housing, a ecable trained 1 over said pulley and extending througha an end of said arm, and a coil spring havingone en'd con- *nected'tosaid cable and its other end connected lt'o' said partition. 

